The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it may be described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present technology.
Ionic liquids are a class of electrolyte applicable to lithium metal-based battery technology. Ionic liquids, or “molten salts”, are composed of ionic species, and most examples consist of a single/simple cation/anion pair. Their main attraction, in battery applications, include little-to-no vapor pressure below 100° C., unlimited combination of ions (like a designer solvent), wide and stable potential windows, non-flammable characteristics, ability to exclude water, high conductivities, and high solubility of metal salts. These attractions have led to ionic liquids being of great interest as compared to organic solvents.
Water reacts spontaneously with lithium metal, as well as other alkali and alkaline earth metals. Few, if any, ionic liquids or other electrolytes provide favorable lithium cycling results in the presence of water in the electrolyte. This is despite the well-known water exclusion capability of ionic liquids.
Accordingly, it would be desirable to provide an ionic liquid for a lithium electrolyte that permits stable electrochemical cycling capability while significant water is present in the electrolyte.